Centrifugal apparatus



May 25, ,19371 E. ROBERTS 2,081,840

CENTRIFUGAL APPARATUS Filed June 23, 1934 @wo wn@ Patented May 25, 1937l CENTRIFUGAL APPARATUS Eugene Roberts, Hastings, N. Y., assigner to -The Western States Machine Company,A New York, N. Y., a corporation of Utah Application June 23, 1934, vSerial No. I132,116

ZCIaimS.

This invention relatesto centrifugal apparatus of the type used in refining sugar or the like and is intended to facilitate the unloading of the basket and also Vavoid injury to the bottom closing valve or to such accessory apparatus as the discharger plow and the sprayer, which perform their functions inside the basket itself.

As is well known to those familiar with centrifugals of this type, the centrifugal basket is secured to the lower end o a revoluble suspension shaft and is provided with a radial arm spider securing the bottom ring foi the basket to the lower end of the suspension shaft, thus providing sector-shaped openings between the bottom ring and the `shaft through which the material may be discharged by means of an unloading plow, which shears the annular sugar wall from the inside of the basket wall and deects it into the discharge openings.

Since the plow spindle and plovar must be inserted inside the top rim of the basket to unload the material and since the sprayer device must also project down into the basket to properly perform its function of washing the sugar, it is evident that the removable circular bottom valve or plate, which normally closes the open spider during the centri'fuging operations, should be small enough to permit its removal in order to allow .the unloading of the basket and it has been the universal practice to provide a retaining hook infront of the basket shaft, some distance above the top of the casing or curb surrounding the basket, to support the valve while the basket is being unloaded.

By reason o .these various conditions it has been the universal practice to maire the open bottom supporting spider of such diameter that the radial distance from the circumferential edge of the spider opening does not exceed the width in a radial direction of the bottom ring, There are several objectionable features about such a bottom construction for this type of basket. in the first place, it leaves a bottom ring or shelf inside the periphery of the basket between `10 and 12 inches wide, while the sugar wall supported thereon is not usually in excess of 6 inches in thickness.' The result is that when the plow penetrates the sugar wall at the top the material slides down on this shelf and accumulates there, so that at the bottom the plow has very much more mass resistance to overcome than should be the case and it is therefore subjected to a very severe pressure. Furthermore, the accumulation of the broken down material tends to choke the relatively small openings through the basket spider and this fur- (Cl. 21o-'10) ther interferes with the quick discharge of the basket.

Another fault with this construction is that oftentimes the circular plate or valve is dropped from its overhead position and causes injury to the delicate sprayer and also by its impact against the bottom has its edge thrown out oi" true so that the valve fails to completely close the bottom opening aslit should do.

After much study of these diiculties I have provided a construction and arrangement permitting a very substantial enlargement of the spider opening in the bottom, so that the bottom shelf or ring is made much narrower than the radial distance from the center of the' basket to the rim of the spider, thereby greatly facilitating and hastening the unloading of the basket and relieving the discharger plow of unnecessary strains and stresses, while at the same time preventing injury to the bottom valve or to the sprayer when the discharge valve is lifted to inoperative position to permit unloading.

This and other features of the invention will be particularly described in the following specification and will be defined in the claims hereto annexed.

In the drawing I have illustrated a simple and convenient form of construction embodying the principles of this invention, in which- Fig. 1 is a vertical section taken through a centrifugal basket and curb showing the suspension of the bottom valve in order to secure the advantages of this improvement, the view being a section from front to back of the basket and casing.

Fig. 2 is a front view illustrating the suspension oi the bottom valve for the discharging operation.

in the practice of the invention as illustrated in the drawing,l the surrounding curb or casing, which. largely encloses the centrifugal basket, comprises the imperforate peripheral wall il, the top ring l l which supports the discharger mechanism including the vertically shiftabl plow spindle l2, and the discharger plow or scraper it. The discharger is usually mounted at a position about 45 from the front of the basket on the left hand side of the operator, who stands in front of the machine,'and the sprayer device is mounted on the top i i of the curb or casing practically to the rear of the basket suspension and driving spindle 5.

The basket comprises the usual, well known perforated cylindrical peripheral wall l with reenforcing hoops or rings E and a bottom ring 3 formed with a radial arm spider t, which is bolted to the enlarged conical lower end of the spider 5.

The top ring 8 of the basket partly closes the basket at the top and serves to retain the sugar wall which is built up between the bottom ring 3 and the top ring 8 by centrifugal force, since the material fed into the basket for treatment is in a. semi-fluid mass, as is well known to those familiar with the art.

The bottom ring 3 of the basket is much narrower in radial width than has heretofore been the practice and it is normally closed, while the machine is in operation, by means of a valve in the form of a circular plate or disc 8 provided with a central flanged opening at 6- to fit around the enlarged lower end of the spindle 5, justy above the hub portion of the spider.l The bottom valve is provided with two approximately U-shaped handles 1 on opposite sides of the center to permit lifting the valve from its closure position to allow discharging of the load.

In the lay-out actually shown inthe drawing, assuming the basket to be one that is 40 inches in diameter, the size most commonly used in sugar refining, the diameter of the spider rim 4 may be 24 inche's or even somewhat larger, leaving the annular shelf or bottom ring 3 only 8 inches or less in width, instead of leaving it from 10 to 12 inches in width. This brings the discharge openings in the spider very much closer to the peripheral wall of the basket so that when the sugar wall is being broken down there is no possibility of large accumulation of material and therefore, as the plow descends from top to bottom in performing its unloading function, the material discharges through the large bottom opening as fast as it is broken down and there is no chance for accumulation of material as heretofore to resist the operation of the plow near the bottom and subject it to undue stresses.

' It is clear that since the bottom valve or plate 6 with the above described construction must be substantially larger in diameter than has heretofore been the case, that the old practice of removing the valve from the basket and supporting it on an overhead hook will be attended with great difliculty and with certain injury to the valve and the sprayer. To meet this situation I have provided a suspension hook I4 that comes down below the level of the top of the casing sufciently to allow the valve to be supported inside the basket with its forward edge slanting sharply upward and its rear edge slanting sharply downward. By suspending it in this relative position with relation to the path of movement of the plow I3 and the plow spindle when the plow is inserted in the basket, there is provided suillcient room for the introduction of the plow and its proper operation, while at the same time there is not the slightest danger of injury to the delicate sprayer device. Furthermore, should the operator drop the valve accidentally from this low position, the impact of the valve lfollowing such a slight distance would not cause any distortion lor injury to the valve itself. which would resuit in leakage.

'I'he suspensionl means may be of any suitable sort. In the present case I have used asuspension chain Ii for suspending the hook at approximately the level of the top of the basket ,and to prevent swaying the upper portion of the suspension chain or element Il is divided into two branches I6n extending up to well, separated brackets or supporting members i1, which may be secured to the overhead structure of the centrifugal apparatus. p

As a result of this new construction and arrangement the unloading of the basket is greatly facilitated; the obstruction to the action of the plow, by the accumulation of the broken down material on the bottom of the basket, is prevented so that the unloading of the basket, is hastened and excessive stress on the plow is avoided. Moreover, the injuries to the bottom valve and to the sprayer device, which frequently occur under present practice, are Wholly` eliminated.

For the sake of illustration, we may assume a basket of the standard interior diameter of 40 inches. In good practice the basket shaft will have a diameter of about 31/2 inches withthe cone enlargement at the bottom 8 inches in diameter, corresponding to the diameter of the central hub of the spider. If the radial measurement from the hub of the spider to itsrim be 8 inches, giving an over-all diameterof 24 inches, the sugar supporting shelf or bottom ring would be only 8 inches wide and, in fact, it might be made even narrowerthan this by making the spider part of the bottom 26 inches in diameter. therefore be seen that the rim of the spider inl such case may have a radial dimension 50% or more greater than the width of the bottom ring, whichv arrangement previous to this invention would have been considered utterly impracticable.

'I'he use of a substantially at disc-like closure valve with its lifting loop or suspending loop or handle 1 located relatively near the periphery made it possible to suspend the valve at such an acute angle to the shaft axis as t'o avoid clashing between the internally suspended Valve and the interior discharger and spraying devices, because it brings all portions of the valve, that are next to either the spraying devices or'the discharger mechanism, so close to the central shaft that there is no longer any danger of meeting with the injuries that were hitherto unavoidable if the spider openings were enlarged to the most effective and satisfactory proportions. Since the discharger is located in the front half of the basket and the sprayer device in the rear half', the front and rear portions of the valve, when'suspended in the manner described are amply well spaced from both of these devices.

What I claim is:

1. In a centrifugal machine the combination with a revoluble suspension shaft, of a centrifugal basket having a bottom comprising a central supporting hub for attachment to the supporting and driving shaft, radial arms, and a circumferential flange connecting the outer edge of said arms and forming an open spider for the discharge of material, a at bottom ring surrounding said spider and connecting it with the peripheral wall of the basket, a substantially nat bottom closing valve normally covering the spider andprovided near its periphery with a suspending loop, and suspension means located near to and infront of the shaft at approximately the level of the top of the basket, said suspension means being supported by upwardly extending divergent suspension chains whereby the valve is permitted to hang in an oblique position at an acute angleto the axis of the shaft.

2. Centrifugal apparatus comprising in combination, a main spindle, a basket having a vertical peripheral wall and annular top and bottom rings secured thereto. an open spider including radial arms connecting said annular It will' valve surrounding the main spindle tor closing bottom ring with the main spindle. a stationary curb surrounding said basket having an open top wall permitting acess to the interior of the basket, discharging means including stationary mounting means 'ixed to the top wall of the curb and overlying space between said annular top ring andthe main spindle and a discharger and .discharger spindle mounted on and movable verbasket inside said top ring in position to direct a spray onto'the wall of material in the basket across space between the basket and spindle i away from said uf l,

the openings inside said bottom ring, the inner diameter of said bottom ring being more than one-half the diameter of tghe basket, and means for releasibly supporting said valve within the upper part of the t and curb in a position inclining sharply downwardly and away from said discharging means. whereby to permit free operation of, the discnarger and easy replacement of the valve and to facilitate elimination of dislodged material from the basket while avoidlng interference with the spraying 

